我不知道您需要什么输出,但是这里有关于重复项的信息,也许您还想在重复项上添加unwind。
结果文档
- 产品ID
- 订单(找到重复项)
- 重复项(具有该订单作为重复项的文档)
对于您的数据,将打印
[{
"duplicates": [
"5a760191813a54000b8475f1",
"5a75f6f17abe45000a3ba05e"
],
"order": {
"row": "3",
"seat": "12"
},
"product_id": "5a7628bedbcc42000aa7f614"
}]
查询
(在驱动程序上运行,MongoPlayground无法保持字段顺序,可能会显示错误的结果)
aggregate(
[{"$unwind" : {"path" : "$orders"}},
{
"$group" : {
"_id" : {
"orders" : "$orders",
"product_id" : "$product_id"
},
"duplicates" : {
"$push" : "$_id"
}
}
},
{"$match" : {"$expr" : {"$gt" : [ {"$size" : "$duplicates"}, 1 ]}}},
{
"$project" : {
"_id" : 0,
"order" : "$_id.orders",
"product_id" : "$_id.product_id",
"duplicates" : 1
}
}
])
数据 (我添加了更多的数据)
[
{
"_id": "5a760191813a54000b8475f1",
"orders": [
{
"row": "3",
"seat": "11"
},
{
"row": "3",
"seat": "12"
}
],
"product_id": "5a7628bedbcc42000aa7f614"
},
{
"_id": "5a75f6f17abe45000a3ba05g",
"orders": [
{
"row": "3",
"seat": "12"
},
{
"row": "3",
"seat": "13"
}
],
"product_id": "5a7628bedbcc42000aa7f614"
},
{
"_id": "5a75f6f17abe45000a3ba05e",
"orders": [
{
"row": "3",
"seat": "12"
},
{
"row": "3",
"seat": "13"
}
],
"product_id": "5a7628bedbcc42000aa7f614"
},
{
"_id": "5a75ebdf813a54000b8475e7",
"orders": [
{
"row": "5",
"seat": "16"
},
{
"row": "5",
"seat": "15"
}
],
"product_id": "5a75f711dbcc42000c459efc"
}
]
结果
[{
"duplicates": [
"5a75f6f17abe45000a3ba05g",
"5a75f6f17abe45000a3ba05e"
],
"order": {
"row": "3",
"seat": "13"
},
"product_id": "5a7628bedbcc42000aa7f614"
},
{
"duplicates": [
"5a760191813a54000b8475f1",
"5a75f6f17abe45000a3ba05g",
"5a75f6f17abe45000a3ba05e"
],
"order": {
"row": "3",
"seat": "12"
},
"product_id": "5a7628bedbcc42000aa7f614"
}]
{ "row": "3", "seat": "12" }
,所以存在重复吗?你想在查询之后得到什么输出数据?例如,只需要重复项的“_id”即可吗?还是你想保留所有文档信息? - Takis